Inclosed switch



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March 12, 1929.

March 12, 1929. F. T. WHEELER INCLOSED SWITCH Filed Dec. 29. 1925 2 Sheets-Sheet 2 Patented Mar. 12, 1929.

UNITED STATES PATENT OFFICE.

FRANK T. WHEELER, OF PLAINVILLE, CONNECTICUT, ASSIGNOR TO THE TRUMBULL ELECTRIC MANUFACTURING COMPANY, OF PLAIIJVILLE, CONNECTICUT, A COR- PORATION OF CONNECTICUT INCLOSED SWITCH.

Application filed December 29, 1925.

This invention relates particularly to what are SOIIlGtlHlOS called safety switches in which the switch mechanism proper is inclosed in a steel box which is connected to the conduits for the electric wires.

The main object is to provide a simple, compact and reliable construction which can be readily wired.

Another object is to provide a construction of this character in which the outer box may first be installed with the conduit system and the wires drawn in, after which the switch proper can be readily inserted and connected.

Another object is to provide an inclosed switch construction in which the switch proper can readily be inserted, removed or replaced.

Another object is to provide a switch which can be cheaply made and readily assembled and yet which is practical and safe.

Another object is to provide a switch construction which can be transported and handled in the ordinary channels of trade with a minimum danger of breakage or disarrangement of the parts.

In the preferred form of construction the complete and operable switch proper is mounted on a saddle or cradle which is adapted to be detachably mounted in a switch box or receptacle.

The parts are so constructed and arranged with respect to the switch box as to facilitate installation and wiring.

Fig. 1 is a front view of a construction embodying one form of my invention, the cover of the box being shown open and the switch in its closed circuit position.

Fig. 2 is an external side view of the same with the cover closed, showing parts of the switch in dotted lines in the closed circuit position and also showing the switch blade in open circuit position in dot and dash lines.

Fig. 3 is a transverse section on the plane of the line 33 of Fig. 1.

Fig. 4 is a perspective view showing the box open and the switch unit in position for assembly in the box.

Fig. 5 is a rear view of the switch unit and saddle.

Fig. 6 is a perspective view of parts of the switch and fuse socket elements.

The box 10 may be of any suitable con- Serial No. 78,071.

struction provided with a cover 11 which is preferably hinged along one edge and preferably provided at the other edge with a catch or latch device 12. The box is also preferably provided with knock-outs such as 13 and 14. on its ends and sides respectively at such points as it is likely that conduit connections may be attached.

The switch unit has an insulating block or base 15 to which the various current carrying parts are attached. The stationary switch contact 16 and the movable contact 17 may be of any suitable type, in this case similar to those usually employed in knife blade switches. The stationary contact is provided with a circuit terminal 18 and these two parts are connected to the block 15 by means of a screw 19 in the usual manner. The switch blade 17 is hinged to the post 20 which is secured to the base 15 for instance by means of a screw 21 in the usual manner. The switch is preferably provided with a protective device or means for mounting one as for instance a fuse socket having a screw threaded shell terminal 22 and the center screw terminal 23 of any suitable form. The screws 21 and 23 are connected by link 24 in the back of the base 15. The screw shell 22 is provided with a circuit terminal 25 which is connected to the flange of the shell 22 and insulated from the center screw 23 by means of an insulating washer 26 in the usual manner.

The side of the base 15 opposite the switch contacts is provided with a terminal strip 27 which is secured to the base by one or more screws such as 28 and may be provided with a number of binding screws 29 for convenience in wiring.

I also prefer to provide the base 15 with an integral insulating barrier 30 between the term nal plate 27 and the switch members so as to keep the ends of the wires separated and prevent arcing between points of opposite polarity.

The switch base 15 is mounted on a saddle or cradle 31 to which it is secured by one or more screws such as 32. This saddle is of U-shaped Cross section and has sides 33 and 33" which fit between the sides of the box and are provided with lugs such as 34 and 35 which are adapted to be supported on the lugs 36 and 37 formed in the opposite sides of the box. The parts may be readily cured together by ordinary screws as shown in Figs. 1 and 3. By arranging these pairs of lugs diagonally as shown in Fig. 1 it is possible to secure the saddle in place with only two screws. The operating member or crank 38 is pivotally supported by the saddle 31 and for this purpose is preferably provided with bearings 35) and 40 in the opposite side plates 33 and 33 respectively. The crank 38 is connected to the switch blade 17 for instance by means of a forked arm 41 preferably forn'ied of insulating material so that the operating crank is insulated from the switch. The operating member is also preferably provided ith an external operating handle 42 at one side. The operating handle and crank may be conveniently formed of one piece or rod or wire which can be very readily inserted in the plate 33 and sprung into place in the side plate 33. A stop lug 43 at one edge of the plate 33 serves as a limiting stop when throwing the switch to the open circuit position. The side wall of the box 10 is preferably pro vided with a slot 44 for the bearing 89 to permit the insertion of the switch mecha nism into the box without disturbing the operating member. This slot 44 serves as a locating or positioning guide for the hearing 39 when the switch is to be inserted in the box. The box may also have a slot 44 which serves as a guide for the bearing 40.

Although I have shown a slot in each side of the box for receiving the respective ends of the switch crank, it is obvious that the slot 44 may be omitted if so desired for the reason that the crank is provided with bearings in the sides 33 and 33 of the saddle. In either case the sides 33 and 33 of the saddle will completely close the crank receiving slots in the sides of the box.

When the switch is assembled in the box it will be seen that there a substantial amount of clearance around the switch proper not only at the sides and ends but also under the saddle 31 as shown in Fig. 3. The switch can be readily removed from the box so as to provide a maximum working space in the box for the purpose of securing the conduits or cable connections to the box. This construction makes it possible to use a very small sized box compared with those formerly used in devices of this character. After the conduits are in position the wires or conductors are run into the box and cut off or left with ends sufficiently long to permit convenient Wiring. The switch unit is then secured in position and the ends of the wires attached to the terminals or binding screws in the usual manner.

The engagement of the crank with the slot or slots in the sides of the box, the relative position of the co-operating lugs 34 and 35 on the saddle 'and lugs 36 and 37 on the box and the close proximity of the inner surface of the box cover to the free ends of the saddle, when the cover is closed, all co-operate to practically lock the switch unit in normally operative position independently of any securing screws. In fact, the switch is safely operable even when such securing screws are entirely omitted. In View of the foregoing paragraph, it is obvious that snap lugs on the upper or free ends of the saddle and corresponding holes on the sides of the box (or vice-versa), like the engagement of the catch 12 with the cover slot, may be substituted for the securing screws shown in the drawings without departing from the spirit of the invention.

It will be seen that the switch unit per se carries the operating crank and is a complete and operable combination even when detached. It is therefore possible to manufacture and sell these switch units by themselves for replacement when necessary. The same box can be used for switches of different capacities. It is also possible to substitute a switch of a different capacity without disturbing the box installation.

A special advantage of this construction is that the workmen can make all box and conduit connections and complete all adjacent plastering, painting and Woodwork before the switch proper is installed. Prior to installing the switch proper, the box may be closed and sealed or locked thus keeping out dirt and protecting the unconnected ends of the circuit wires.

The saddle construction being resilient forms a sort of spring cradle or mounting for the switch and relieves the switch of the shocks to which it is likely to be subjected in shipping and handling and it thus prevents breakage and injury to the parts.

Although I have illustrated only a single pole switch, it should be understood that the invention is not limited to this particular form or type of switch. It should also be understood that various modifications in details may be made without departing from the spirit or scope of my invention.

I claim:

1. An inclosed switch construction com prising a box and a switch unit mounted in said box, said unit including a saddle, an insulating base mounted on said saddle, switch contacts carried by said base, said box and saddle having oppositely disposed positioning and attaching lugs, and a switch operating member carried by said saddle and connected to one of said switch contacts and having an operating member extending outside of said box and a cover hinged to the box independently of the switch unit, said switch unit being removable only when the cover is open.

2. The combination of a box having a hinged cover and a slot in a side wall, a saddle detachably mounted in said box, a

complete and separately operable knife switch unit including appurtenant terminals and contacts mounted on said saddle and an operating member pivoted in said saddle and having a swinging handle extending through said slot, said switch unit being re movable from the box when the cover is open and means for holding the cover closed independently of the switch unit.

3. The combination of a box having a cover and having a guide slot in one side, a saddle detachably mounted in said box, a complete and separately operable switch mounted on said saddle and an operating member supported by the saddle and guided in said slot and having an operating handle extending through said slot and means for holding the cover closed independently of the swltch unit.

4. The combination of a box having a hinged cover and a guide slot, a saddle detachably mounted in said box, a complete and separately operable switch mounted on said saddle and an operating crank pivoted in said saddle and guided in said slot and having a handle extending outside said box and a latch secured to the box and coacting with the cover to hold it closed independently of the saddle and switch.

5. The combination of a box having a hinged cover and a guide slot, a saddle detaehably mounted in said box and positioned by said slot, a complete and separately operable switch including appurtenant terminals and contacts operably mounted on said saddle, an operating member pivoted in said saddle and having a handle extending through said guide slot and a stop for said operating member carried by said saddle.

6. In an inclosed switch, a box having a slot, a cover for the box, and a removable switch unit in the box including a saddle, a switch member and an operating member therefor mounted on said saddle, the said operating member extending through the slot in the box to permit external operation of the switch member and the saddle being positioned to cover the said slot when the switch is in operable position in the box.

7. In an inclosed switch construction, a box having a slot, a cover for the box and a switch unit in said box, said unit including a saddle, a switch member and an operating member therefor mounted on said saddle, the operating member extending through the slot in the box to permit external operation of said switch member, the saddle being positioned to cover the slot in the box and the switch unit being readily removable as a completely assembled and operable unit.

8. An inclosed switch construction including a box having a slot, a cover for the box, a saddle detachably mounted in said box, a switch and operating means therefor mounted on said saddle, said operating means extending through the slot in said box to permit external operation of said switch and said saddle interfitting with said box to cover said slot.

9. An inclosed switch construction including a box, a cover for said box, a removable frame in said box and a complete switch unit mounted on said frame, said box, cover and frame members being provided with lugs to secure said switch unit in operable position in said box when the cover is closed independently of other securing means, all the line wire connections being carried by and removable with said switch unit.

10. An inclosed switch construction comprising a box having a hinged cover, said box having lugs projecting inwardly from opposite sides, a U-shaped saddle member having lugs adapted to register with and be supported by the lugs in said box, screws for fastening the lugs of said saddle member to the lugs in said box, said saddle member being shallower than said box to leave a passage between the bottom of the saddle member and the bottom of the box, and said saddle member being shorter than said box to leave open spaces in the ends of said box, a switch unit secured to said saddle member and including stationary and movable contacts, wire terminals, and a swinging operating member, said switch unit belng operable as a switch independently of its position in said box and means for holding the cover closed independently of said saddle.

11. An inclosed switch construction comprising a box, a cover therefor, a removable frame mounted in the box, a complete switch .unit supported by said frame and including stationary and movable contacts, an operating member for the movable contact and line wire terminals, said box cover and frame having inter-fitting and abutting means whereby when the cover is closed the switch is held by the cover in operable position in said box and means for holding the cover closed independently of the switch unit.

12. In an electric switch, a U-shaped saddle formed of sheet metal and having a bottom with resilientside arms, an insulating switch base secured on the bottom of the saddle and between the side arms, circuit terminals, fuse terminals, and switch members all mounted on the face of said base, said switch members consisting of a stationary contact connected to one circuit terminal and a hinged blade connected to one of the fuse terminals, the other fuse terminal being connected to the other circuit terminal and an operating crank pivoted in said side arms and connected to said switch blade.

FRANK T. XVHEELER. 

